Patients with Bipolar Depression and ASIB will be recruited in both inpatient and outpatient settings and, following informed consent, will be given an intravenous infusion of ketamine 0.5mg/kg over 40 minutes. Those who exhibit a satisfactory clinical response to ketamine will be randomly allocated to NRX-101 or to a comparator group. The primary outcome variable is time to relapse as defined by a return to baseline in either depression or suicidality as determined by the treating physician or the need to institute a new treatment plan.